"BANKING" FURNACES AND CUPOLAS. 129
the lapse of many hours, Mr. Knoeppel simply closed all air openings tightly with clay and sand, and covered the top of the stock at the charging door with fine dust coke. When the blast was started, about sixteen hours after the shut-down, the melting went on in good shape, as in the usual practice. This was done in a cupola of about 56 inches.inside diameter. One factor assisting to make Mr. Knoeppel's plan so successful was the fact of the iron not having started to melt when the break-down occurred. Mr. Knoeppel's experience, combined with that recited by the author in "American Foundry Practice," above noted, may suggest expedients which may often be profitably adopted.g the bottom '' can only be told by practice. In endeavoring to follow such a practice the management of the cupola must be in intelligent hands, as it can be readily seen that to charge a cupola ignorantly or carelessly, as is often done, would result in leaving iron at a level with the tuyeres, or all on one side of the cupola, so that it could not be melted at the end of a heat. These ideas are not presented with the expectation that all founders are going to drop their present methods to adopt the plans outlined; they are simply offered as suggestions to evolve ideas which may favor the inauguration of new practices that to-day might seem absurd and impracticable.